Recent findings that antigens which have undergone certain chemical modifications preferentially induce cell mediated immunity (without concomitant induction of humoral antibodies) to the native prompt investigations into the potential of this approach for the immunological control of neoplasia. The proposed research is aimed at the assessment of the effect of chemically modified tumor associated antigens on their immunogenic potential in immunoprophylaxis and immunotherapy. The immunoprophylactic capacity of these modified antigens will be assessed in experimental animals utilizing transplantable tumor lines; the immunotherapeutic capacity will be investigated under both experimental and clinical situations. The effect of the preparations will be monitored by in vivo as well as in vitro methods.